Women who are at risk of giving birth prematurely could be spotted early just by looking at the bacteria that’s in their reproductive tract, a new study hinted.

Small changes to vaginal bacteria were found to be strongly connected with births before 37 weeks of pregnancy.

The study shows that the shift in bacteria can be an indication that the waters are likely to break too early in the pregnancy.

Changes to the “healthy bacteria” mix

Changes to the usual health mix was also linked to an increased risk of harm to both mum and baby, such as a greater chance of sepsis – a rare but serious infection that can lead to multiple organ failure and death.

Lead scientist Dr David MacIntyre, from Imperial College London, said: “This study is one of the first to show that around almost a half of pregnant women may have an unbalanced vaginal microbiota before premature rupture, providing further evidence of the role of bacteria in some cases of premature births.

“Crucially, our findings identify two different groups of women with premature rupture – one group in which targeted antibiotics may be beneficial and the other in which this same treatment may actually be detrimental.”

Lactobacillus could help predict premature birth

The research team collected swab samples from 250 pregnant women who either did or did not present risk factors for giving birth prematurely.

Twenty-seven of the mums went on to give birth before 37 weeks.

Another 87 samples were taken from women who visited hospital after their water broke prematurely.

The findings, published in the journal BMC Medicine, revealed that breaking waters early was linked with falling levels of a bacteria called Lactobacillus, as well as increases in other types of bacteria.

Previous research has found that during pregnancy the Lactobacillus species of bacteria tends to colonise the vagina, reducing the amount of other bacteria present.

Standard antibiotics can be harmful

While standard antibiotic treatment can help reduce infection in most women whose waters break early, for others the practice can be harmful.

One theory behind this is that the antibiotics could destroy the “good bacteria” and allow more dangerous bacteria to take their place.

Co-author Dr Richard Brown, also from Imperial College, said: “Our results suggest that a more personalised approach targeting only those women likely to benefit from antibiotics may prove more beneficial than the current ‘one treatment fits all’ approach.”

Speaking about the potential for future research, Professor Siobhan Quenby, from the Royal College of Obstetricians and Gynaecologists, commented: “There is now the exciting possibility of a future where women are tested and given the best antibiotic for them as an individual.”